how to cheak a battery is still out putting the near same amps ?

[Screwdriver]

Maximum no load voltage (after the battery pack is fully charged) will give you the most reliable information to it’s overall status. The only other way to. Tell if you have a failing cell is to check the voltage of the individual cell.

You need to take suitable precautions when playing with battery pack innards. It is extremely easy to short one out and they are phenomenally powerful components.

 

[armalites]

ok done a test cut both batterys cut 2 good slots (might have been leaning more than I should if in 6mm steel ish I'm not sure what it is both went down to 1 light
And grinder getting warm so had a break for 20 mins come back another 6 cuts on the 5amp one and on my 4 amp another 6 cuts the 5amp had a little more oomph then the 4amp but was low on power so stopped there as lithium batterys dont like taking down to low battery

This seams rather low to me on both batterys as if doing this as a job they word not be worth there salt great if your doing car stuff etc or 2mm but much more then that they seam not fit to use

The Dewalt batteries will stop dead when they are too low(like every other brand I'm sure). No issues running them till they stop

Grinders are battery hungry but that's the benefit of having multiple batteries. Battery grinders aren't designed for for cutting metal all day long but if you have enough spare batteries they will do it fine. The big benefit is convenience.

 

[angellonewolf]

as looking at it compair the 4 amp newer unit i got the 5amp seam to be ok not great might ave a bit more than the the nwerr 4 amp ive got take it back ? as i got it for £20 it will do for what i need unless i have more neg feed back on it

its 2nd hand and used so i need to expect its not the same as new but if i realy need a good battery i need to spend the money and buy new

 

[angellonewolf]

The Dewalt batteries will stop dead when they are too low(like every other brand I'm sure). No issues running them till they stop

not that i know but looking on the net seam to say dont drain it as lion batterys like a half charge rather than a dead charge and refill

or you will damage the battery

 

[badabec]

View attachment 211464

That looks remarkably like my welding on the top surface, have you been down my bin?

 

[Turbo]

yes was from a shop but 2nd hand i did ask is it working ok but i know its hard to test how old the battery is and how good it is and i cant see them after a couple of months doing a refund as the battery is knackard as they will just say its 2nd hand and you could have used it 8 hours a day for the last 2 months

Warranty on new cordless power tools rarely covers batteries so I would it will cover used ones!

My test method for drill batteries uses a lump of 4" thick mahogany & a box of 5x70 screws. I see how many screws it can put in & remove before it goes flat in comparison to a known good battery. A good 2ah liion battery on my 18v Hitachi drill can do around 40-50 screws, a bad battery puts in the first few ok then dies quite quickly, maybe 8 screws altogether!

 

[angellonewolf]

That looks remarkably like my welding on the top surface, have you been down my bin?

that piece is my scrap bit that i warm up rods on befor going to what im welding and its been around since i started welding so yea the some carp welds on there

but depending on the angle im welding it can still look carp

 

[eddie49]

not that i know but looking on the net seam to say dont drain it as lion batterys like a half charge rather than a dead charge and refill or you will damage the battery

For a reputable brand, the protection circuits built-in to the battery and/or the cordless tool will take into account the recommended and safe limits for over-discharge, and so as armalites said, there's no harm in running the tool until it shuts down by itself.

 

[armalites]

not that i know but looking on the net seam to say dont drain it as lion batterys like a half charge rather than a dead charge and refill

or you will damage the battery

For sure if you want them to have a long life you are better to be topping them up than charging from flat but it's not always practical in the real world. If you were doing that you would need even more batteries and chargers.

Batteries are cheap as chips relative to what they used to be. I remember when I had my first Dewalt Ni-Cad stuff, a new battery was about £90 for a 2ah unit and that was over 20 years ago so in real terms they probably cost 1/3 of what they were then.

It sounds like your new battery works fine, what I've found with duff Li-Ion batteries is when they die they will look like they charge fine or they will charge very quickly but as soon as you put them on a tool they don't work.

All my point is it's a £20 battery and it works, don't overthink it. Even if it has 20% less run time it will still do the job you need of it and will be £20 well spent.

You don't want to be accused of battery discrimination

 

[angellonewolf]

^^^yes seams as its near to as best as it can be for a 2nd hand battery and as said its £20and now i got 3 batterys and 3 tools just now need 2 more batterys and a twin charger

 

[armalites]

^^^yes seams as its near to as best as it can be for a 2nd hand battery and as said its £20and now i got 3 batterys and 3 tools just now need 2 more batterys and a twin charger

It's a slippery slope, you soon end up with 8 batteries and 5 chargers just in case 7 of the batteries are dead when you want to drill one hole